INFO: task udevd:4286 blocked for more than 143 seconds.
Not tainted 6.1.147-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22624 pid:4286 ppid:3638 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
device_lock include/linux/device.h:837 [inline]
uevent_show+0x16c/0x320 drivers/base/core.c:2669
dev_attr_show+0x50/0xb0 drivers/base/core.c:2372
sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59
seq_read_iter+0x49b/0xd50 fs/seq_file.c:230
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0e3e6a7407
RSP: 002b:00007ffc56cd5310 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f0e3ed7c880 RCX: 00007f0e3e6a7407
RDX: 0000000000001000 RSI: 000055aa1b875d30 RDI: 0000000000000008
RBP: 00007f0e3e7efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007f0e3e7efea0 R14: 0000000000000000 R15: 000055aa1b86bf30
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b7b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bfd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
6 locks held by kworker/1:0/22:
#0: ffff888144286538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff8880282f4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#2: ffff8880282f4190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x54e0 drivers/usb/core/hub.c:5845
#3: ffff88807d535190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff88807d535190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
#4: ffff88807ec0a118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#4: ffff88807ec0a118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
#5: ffffffff8c9d79b0 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xec/0x2a0 kernel/umh.c:218
1 lock held by khungtaskd/28:
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:3/51:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
2 locks held by getty/4031:
#0: ffff888030e76098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
4 locks held by udevd/4286:
#0: ffff88802fc0d790 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
#1: ffff88802833f488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3b0 fs/kernfs/file.c:154
#2: ffff88805656ee88 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3b0 fs/kernfs/file.c:155
#3: ffff88807d535190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff88807d535190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3620 Comm: syslogd Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:cr4_update_pce_mm arch/x86/mm/tlb.c:467 [inline]
RIP: 0010:switch_mm_irqs_off+0x7ae/0xb10 arch/x86/mm/tlb.c:649
Code: 8d b7 a8 05 00 00 4c 89 f7 be 04 00 00 00 e8 a9 90 97 00 4c 89 f0 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 9b 01 00 00 41 83 3e 00 <74> 0e e8 5b 99 c7 ff bf 00 01 00 00 31 f6 eb 07 be 00 01 00 00 31
RSP: 0018:ffffc90003187560 EFLAGS: 00000046
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff81395447
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807dfd1c28
RBP: ffffc90003187630 R08: dffffc0000000000 R09: ffffed100fbfa386
R10: ffffed100fbfa386 R11: 1ffff1100fbfa385 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88807dfd1c28 R15: ffff88807dfd1680
FS: 00007faaf5818c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbd88183178 CR3: 0000000031642000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
context_switch kernel/sched/core.c:5229 [inline]
__schedule+0xe99/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x97/0x280 kernel/time/timer.c:1941
__skb_wait_for_more_packets+0x39a/0x580 net/core/datagram.c:120
__unix_dgram_recvmsg+0x282/0xd70 net/unix/af_unix.c:2464
sock_recvmsg_nosec net/socket.c:1022 [inline]
sock_recvmsg net/socket.c:1040 [inline]
sock_read_iter+0x2bf/0x370 net/socket.c:1121
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faaf5968407
Code: Unable to access opcode bytes at 0x7faaf59683dd.
RSP: 002b:00007ffc7721f430 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007faaf5818c80 RCX: 00007faaf5968407
RDX: 00000000000000ff RSI: 0000562918553950 RDI: 0000000000000000
RBP: 0000562918553910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056291855399a
R13: 0000000000000000 R14: 0000562918553950 R15: 00005628f40add98